title: Clinical factors associated with weight loss outcomes after Roux-en-Y gastric bypass surgery.
abstract: OBJECTIVE
  Gastric bypass surgery is an effective therapy for extreme obesity. However, substantial variability in weight loss outcomes exists that remains largely unexplained. Our objective was to determine whether any commonly collected preoperative clinical variables were associated with weight loss following Roux-en-Y gastric bypass (RYGB) surgery.
  
  
  METHODS
  The analysis was based on a prospectively recruited observational cohort of 2,365 patients who underwent Roux-en-Y gastric bypass surgery from 2004 to 2009. Weight loss was stratified into three major phases, early (0-6 months), nadir, and long-term (>36 months). Multivariate regression models were constructed using a database of over 350 variables.
  
  
  RESULTS
  A total of 12-14 preoperative variables were independently associated (P < 0.05) with each of the temporal weight loss phases. Preoperative variables associated with poorer nadir and long-term weight loss included higher baseline BMI, higher preoperative weight loss, iron deficiency, use of any diabetes medication, nonuse of bupropion medication, no history of smoking, age >50 years, and the presence of fibrosis on liver biopsy.
  
  
  CONCLUSIONS
  Several variables previously associated with poorer weight loss after RYGB surgery including age, baseline BMI, and type 2 diabetes were replicated. Several others suggest possible clinical interventions for postoperative management of RYGB patients to improve weight loss outcomes.
authors.affiliation: Geisinger Obesity Research Institute, Geisinger Clinic, Danville, Pennsylvania, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Still
authors.forename: G Craig
authors.initials: GC
authors.lastname: Wood
authors.forename: Xin
authors.initials: X
authors.lastname: Chu
authors.forename: Christina
authors.initials: C
authors.lastname: Manney
authors.forename: William
authors.initials: W
authors.lastname: Strodel
authors.forename: Anthony
authors.initials: A
authors.lastname: Petrick
authors.forename: Jon
authors.initials: J
authors.lastname: Gabrielsen
authors.forename: Tooraj
authors.initials: T
authors.lastname: Mirshahi
authors.forename: George
authors.initials: G
authors.lastname: Argyropoulos
authors.forename: Jamie
authors.initials: J
authors.lastname: Seiler
authors.forename: Marco
authors.initials: M
authors.lastname: Yung
authors.forename: Peter
authors.initials: P
authors.lastname: Benotti
authors.forename: Glenn S
authors.initials: GS
authors.lastname: Gerhard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000713:Anastomosis, Roux-en-Y; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2; D005260:Female; D015390:Gastric Bypass / Q000379:methods*; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000601:surgery*; D011446:Prospective Studies; D016896:Treatment Outcome; D015431:Weight Loss; D055815:Young Adult